Heretofore, most dryer-added fabric conditioning products contain a perfume to deposit some fragrance onto the laundered fabrics, both to provide an olfactory aesthetic benefit and to serve as a signal that the fabrics are clean. Fabric conditioning compositions in the art commonly contain perfumes to provide a good odor to fabrics. Typical perfume compounds and compositions can be found in the art including U.S. Pat. No. 4,145,184, Brain and Cummins, issued Mar. 20, 1979; U.S. Pat. No. 4,209,417, Whyte, issued Jun. 24, 1980; U.S. Pat. No. 4,515,705, Moeddel, issued May 7, 1985; and U.S. Pat. No. 4,152,272, Young, issued May 1, 1979. Due to the high energy input and large air flow in the drying process used in the typical automatic clothes dryers, a large part of the perfume provided by such fabric conditioning products has been lost out the dryer vent. Even for the less volatile components, only a small fraction remains on the fabrics after the drying cycle. The loss of the highly volatile fraction of the perfume is much higher. Usually the loss of the highly volatile fraction is substantial, often practically total. Due to this problem most laundry perfumes have been composed mainly of less volatile perfume components to survive the drying cycle and thus provide better “fabric substantivity.” The main function of a small fraction of the highly volatile perfume components in these perfumes is sometimes just to improve the fragrance odor of the product itself, rather than significantly impacting on the subsequent fabric odor. However, some of the non-substantive, volatile perfume ingredients can provide a desirable fresh and clean impression to the fabrics, and it is highly desirable that these ingredients be deposited and present on the dried fabrics. Methods have been devised using perfume carriers to deliver these desirable, highly volatile perfume ingredients from dryer-added fabric conditioning products. Thus, U.S. Pat. No. 5,102,564 issued Apr. 7, 1992 to Gardlik et al. discloses the use of cyclodextrins to encapsulate the volatile perfume ingredients for use in dryer-added fabric conditioning sheets, to deliver such perfume to the fabrics. U.S. Pat. No. 5,830,835 issued Nov. 3, 1998 to Severns et al. discloses the use of pro-perfumes which are subsequently hydrolyzed to release volatile perfume ingredients in dryer-added fabric conditioning compositions. U.S. Pat. Appl. Publ. No. 2003/0013632 A1 published Jan. 16, 2003 to Santos et al. discloses the use of zeolites as a perfume carrier to deliver volatile perfume ingredients from dryer-added sheets. Efforts are continued to find ways to deliver the neat, free volatile perfume ingredients without having to use the expensive and/or complicated perfume carriers.
Dryer-added fabric conditioning products provide a better convenience to the consumer as compared to the rinse-added fabric conditioning products because they spare the consumer the requirement of having to be present right at the beginning of the rinse cycle.
There are two main types of dryer-added fabric conditioning products, namely, single use product and multiple-use products. Single use products, most commonly in the sheet form coated with a fabric conditioning active composition, calls for adding a single sheet into an automatic clothes dryer containing a wet laundry load, at the beginning of the drying cycle. Examples of this type of product are disclosed in U.S. Pat. No. 3,442,692 to Gaiser and U.S. Pat. No. 3,686,025 to Morton et al.
Multiple-use fabric conditioning products are placed in the interior of the dryer to release the fabric conditioning active to successive laundry loads. Each multiple-use product lasts many drying cycles, from a few cycles to about 50 or more cycles, and thus provides a better convenience to the consumer than single use products. One type of multiple-use products consists of a dispenser that is attached to the interior of an automatic clothes dryer, said dispenser having a permeable surface and containing a fabric conditioning active composition that is a solid at room temperature and is softenable at the operating temperature of said clothes dryer. In use, the hot operating temperature of the clothes dryer softens or melts the conditioning active which then passes through the permeable surface and is transferred to the fabric being treated by contact to provide the desired fabric conditioning benefits. Multiple-use products of this type are disclosed, e.g., in U.S. Pat. No. 3,967,008 issued Jun. 29, 1976 and U.S. Pat. No. 4,004,685 issued Jan. 25, 1977, both to Mizuno et al., and U.S. Pat. No. 4,149,977 issued Apr. 17, 1979 to Morganson et al.
Another type of multiple-use products has the conditioning active not covered by a permeable surface, but is instead exposed to be transferred to the fabric. The products can be attached to the interior of the dryer, as disclosed in U.S. Pat. No. 3,696,034 issued Oct. 3, 1972, U.S. Pat. Appl. Publ. No. 2003/0192197 A1 published Oct. 16, 2003 to Griese et al., and U.S. Pat. Appl. Publ. No. 2003/0195130 A1 published Oct. 16, 2003 to Lentsch et al. The products can also be unattached and tumbled along with the clothes in the dryer interior, as is disclosed in U.S. Pat. No. 3,676,199 issued Jul. 11, 1972 to Hewitt et al. The softener active, which is preferably solid at room temperature, can soften or melt under the clothes dryer operating temperature, such as those disclosed in U.S. Pat. Nos. 3,676,199 and 3,696,034, or only softens at a temperature above the clothes dryer operating temperature, such as those disclosed in U.S. Pat. Appl. Publ. Nos. 2003/0192197 and 2003/0195130 A1.
It is very desirable to be able to provide volatile perfume ingredients to fabrics to impart a freshening benefit. Accordingly, there is a need for a dryer-added fabric conditioning composition that can deliver a higher level of volatile perfume ingredients than conventional dryer-added fabric conditioning products. In the fabric conditioning product art, the beneficial effect of the product form on volatile perfume delivery is not known or appreciated. The present invention provides a dryer-added product that can deliver such a perfume benefit.